Mount Bethel Fens

The extreme alkalinity and continuous moisture at Mount Bethel Fens supports rare mosses.

At a glance, the Mount Bethel Fens resembles a collection of meadow-like openings in deciduous forest commonly seen throughout the eastern seaboard. However upon closer examination, the saturated ground characterizing these areas reveals numerous, globally rare calcareous fens – wetlands that have become increasingly rare in eastern Pennsylvania and New Jersey.  

Recognized by naturalists as a turn of the century botanical wonder, the Mount Bethel Fens are fed by springs and seeps with waters rich in calcium, magnesium and other minerals. The extreme alkalinity and continuous moisture produces soils that support rare mosses, plants and animals, including whorled nutrush and brook lobelia. If the delicate balance between the amount of water and chemical composition becomes disrupted at one location, the entire fen complex is affected.    

Since the mid-1980’s, The Nature Conservancy has monitored and managed this complex of fens in partnership with Lehigh University’s Lehigh Earth Observatory. To maintain the integrity of the Mount Bethel Fens, staff hydrologists regularly analyze the water quality at locations upstream and downstream from the fen complex, and collect additional data about rainfall, temperature, relative humidity and other conditions at weather stations located within the project area. While this information shapes conservation efforts at the Mount Bethel Fens, the Conservancy continues to pursue the acquisition of additional land and easements critical to their long-term protection. 

The withdrawal and diversion of groundwater. Invasive vegetation.

Monitoring hydrology. Removing invasive vegetation. Seeking opportunities to acquire land and conservation easements.

Arrival of Dr. Edgar T. Wherry, a world renowned scientist, to study the Mount Bethel Fens in 1920. The donation of 33 acres to The Nature Conservancy in 1996.

Lehigh Earth Observatory, Pennsylvania Department of Conservation and Natural Resources, United States Fish & Wildlife Service, Upper Mount Bethel Township, William Penn Foundation, local communities


Stay Updated

Learn about the places you love and find out how you can help by signing up for Nature eNews.

I'm already on the list Read our privacy policy

Thank you for joining our online community!

We'll be in touch soon with more Nature Conservancy news, updates, and exciting stories.